1. Field of the Invention
The invention relates generally to a catalytic cracking process for solid biomass, and more particularly to a catalytic process characterized by use of at least two reaction zones, optionally with a catalyst/feedstock contact time in the millisecond range.
2. Description of the Related Art
Thermal processes, such as pyrolysis, have been proposed for the conversion of solid biomass material to liquid products. In general, temperatures in excess of 450° C. are required for these non-catalytic processes. The primary liquid reaction products are prone to degradation under these reaction conditions. As a result, products of pyrolysis reactions of solid biomass tend to be of poor quality.
Catalytic processes have been proposed for the conversion of solid biomass materials. The use of catalysts permits operation of the conversion reaction at lower temperatures than those required in non-catalytic pyrolysis. These lower conversion temperatures result in liquid reaction products of better quality. An example of a catalytic process is the biomass catalytic cracking process disclosed in WO2007/128800.
In spite of this improvement, the products of biomass catalytic cracking processes (“BCC”) still suffer from poor stability and high acid numbers.
Thus, there is a particular need for an improved BCC process in which the degradation of primary conversion reaction products is further reduced.